1. Field of the Invention
The present invention relates to a projection apparatus for projecting an image of a film.
2. Description of the Related Art
Conventionally, a film cassette disclosed in Published Unexamined Japanese Patent Application No. 2-272538 (hereinafter referred to as prior art example 1) and a film cartridge disclosed in Published Unexamined Japanese Patent Application No. 2-293742 (hereinafter referred to as prior art example 2) are known as being applicable to projection apparatuses of this type.
The film cassette of the prior art example 1 is arranged so that a film belt is automatically delivered to the outside of the shell of the cassette by rotating a spool in the film advancing direction.
The film cartridge of prior art example 2 is arranged so that the leading end portion of the film can be fed into a film take-up chamber by rotating a spindle in the film advancing direction.
According to the prior art examples 1 and 2, however, the vertical orientation, for example, of an image formed on the film is not taken into consideration during shooting operation. When projecting the image by applying light to the delivered film, therefore, the image shot inclined or inverted with respect to the vertical direction is inevitably projected without correction on a screen. Accordingly, the apparatus must be moved to be corrected in vertical orientation, or otherwise, must be provided with an additional optical system. Thus, the projection process requires much time and labor, and the cost of the whole apparatus is inevitably high.
For example, techniques disclosed in Published Unexamined Japanese Patent Applications Nos. 54-2115 and 55-126225 may be used as measures for obtaining a vertical orientation confirmation signal for a shooting screen.
Disclosed in Published Unexamined Japanese Patent Application No. 54-2115 is an apparatus with a plurality of light emitting elements which can project vertically or laterally written data on the screen, depending on the attitude of a camera.
Disclosed in Published Unexamined Japanese Patent Application No. 55-126225 is an apparatus in which the camera attitude is detected by means of the action of gravity so that data corresponding to the attitude can be printed in a film.
A novel film has recently been developed in which shooting date information, on-the-spot audio information, etc. can be magnetically recorded. The films of the prior art examples 1 and 2 are designed without giving consideration to the magnetic recording of these data.
Usually, moreover, the films applicable to the conventional projection apparatuses are different in luminance, so that the screen luminance of the projected image varies. If the screen luminance is too low, the image is dark and indistinct. If the luminance is too high, on the other hand, the image taxes an appreciator's eyes. When appreciating a plurality of films loaded in a magazine or the like for hours, in particular, the appreciator's eyes are adversely affected and fatigued by the films.
Practically, it is difficult to adjust the screen luminance of the image with every change of the films in order to eliminate these adverse effects.